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1.
Fifty-three primiparous sows were used to study the effects of a high-energy, fat-supplemented diet on sow lactation and rebreeding performance. Sows received either a low [Lo, 12.5 Mcal metabolizable energy (ME)/d] or high (Hi, 16.0 Mcal ME/d) energy sorghum-soybean diet during a 28-d lactation. At weaning, sows were randomly allotted, within lactation treatment, to a low (lo, 5.54 Mcal ME/d) or high (hi, 9.61 Mcal ME/d) energy sorghum-soybean diet until the day of first postweaning estrus. Primiparous sows fed Lo weaned larger (P less than .05) litters than sows fed Hi; however, average pig weight was not affected by lactation treatments. Primiparous sows fed Hi had more backfat at weaning (P less than .01) than Lo sows. In contrast, sow weight was not affected by dietary treatments. Neither lactation nor rebreeding treatments influenced days to rebreeding; however, an interaction (P less than .01) was observed. Mean days from weaning to rebreeding for Lolo, Lohi, Hilo and Hihi sows were 10.0, 7.6, 6.9 and 17.1, respectively. Forty sows were maintained on the same dietary treatments during their second parity. Sows receiving Lo during their second parity farrowed and weaned more (P less than .05) pigs than Hi sows. Multiparous sows fed Hi nursed heavier (P less than .05) pigs on d 21 of lactation and at weaning compared with Lo sows. Sows fed Hi were heavier (P less than .05) and had more (P less than .01) backfat at weaning of their second litter compared to Lo sows. Days to postweaning estrus were not affected by lactation or rebreeding diets. Mean length of the second parity rebreeding interval for Lolo, Lohi, Hilo and Hihi sows was 6.2, 10.2, 7.0 and 10.5 d, respectively. These results suggest that feeding levels during lactation of 12.5 Mcal ME/d or higher supported adequate rebreeding performance. Postweaning feeding levels did not influence days to first estrus. Feeding a high energy diet continuously throughout the lactation and rebreeding phases in primiparous sows may lengthen the postweaning interval to estrus.  相似文献   

2.
Thirty primiparous sows were individually penned in a thermoneutral (20 degrees C) or hyperthermal (32 degrees C) environment and fed a high-starch (corn-soybean meal basal), high-fiber (48.5% wheat bran) or high-fat (10.6% choice white grease) diet from d 100 of gestation through a 22-d lactation to determine the effects of thermal environment and dietary energy source on energy and N digestibility in lactating sows. Voluntary feed intake and total feces and urine output were determined from d 12 through d 14 postpartum. Heat exposure (32 degrees C) depressed (P less than .05) voluntary feed, ME and N intake and lowered (P less than .05) apparent daily N retention. Heat exposure did not alter (P greater than .15) digestibility, expressed as percentage of intake, of dietary energy or N. Dietary additions of wheat bran depressed (P less than .05) the proportion of gross energy retained as ME by 12 and 14 percentage units and the apparent digestibility of N by 2.5 and 4.5 percentage units at 20 and 32 degrees C, respectively, compared with those of the basal diet. Dietary additions of choice white grease did not alter (P greater than .15) energy digestibility but increased (P less than .05) the proportion of N digested and retained in both environments. Apparent ME of the wheat bran, corn-soybean meal mix and choice white grease (determined by difference) was 2.72, 3.70 and 8.43 Mcal/kg DM and was independent of thermal environment. Digestibility of fibrous and starchy feedstuffs was similar in lactating sows and growing pigs allowed to consume feed ad libitum, whereas fat was more digestible in the sows.  相似文献   

3.
A total of 146 primiparous sows was used in four replications of an experiment to investigate the effect of energy intake during a 28-d lactation on sow and litter performance. Dietary treatments consisted of three energy intakes; 10, 12 or 14 Mcal of metabolizable energy (ME) X sow-1 X d-1. All sows were fed equal amounts of crude protein, vitamins and minerals daily, which met or exceeded standard recommendations. The experiment was initiated at parturition. Sow weight and backfat loss during lactation decreased linearly (P less than .001) as energy intake increased. There were no differences in litter size at either 14 d of lactation or weaning. Pig weights on d 14 increased linearly (P less than .05) and litter weights tended to increase linearly (P = .13) as energy intake increased. At weaning, pig weights and litter weights increased (P less than .05) as sow energy intake increased. There were no significant differences in the percentages of sows in estrus by 7, 14, 21 and 70 d postweaning, but sows fed 10 Mcal ME/d had a slightly longer interval from weaning to first estrus than sows fed higher energy intakes. Serum urea concentrations of sows were inversely related to energy intake during lactation. Serum creatinine concentrations were not affected by energy intake. An intake of 10 Mcal ME/d by primiparous sows during a 28-d lactation resulted in reduced sow and litter performance; there was little difference between sows fed 12 and 14 Mcal ME/d.  相似文献   

4.
Three trials involving 118 sows were conducted to evaluate the effects of fat and triamcinolone additions in the diets of late-term gravid sows on pre- and postweaning performance of pigs. Beginning an average of 9 d prepartum, sows were fed daily 1.8 kg of a fortified, corn-soybean meal diet [6 Mcal of metabolizable energy (ME) and 290 g of protein/sow] that was supplemented with 4 Mcal of ME/sow in the form of starch, soybean oil or soybean oil plus 70 mg/sow of triamcinolone, a synthetic glucocorticoid. During a 28-d lactation, sows were self-fed a standard 14% protein, corn-soybean meal diet. The addition of soybean oil to the diet of sows during late gestation did not (P greater than .10) influence the weights of survivability of pigs at birth, 14 or 28 d of age, but increased (P less than .05) the carcass fat content of the pigs at birth. The dietary addition of triamcinolone to the sow's prepartum diet increased (P less than .10) pig weights at birth and 14 d, and tended to increase pig weights at 28 d compared with those of pigs from sows fed soybean oil only. Prepartal administration of triamcinolone depressed (P less than .05) carcass protein content and adrenal weights in pigs at birth or 28 d of age. From weaning (d 28) to 56 d of age, pigs from sows fed soybean oil before parturition, particularly those from sows fed triamcinolone, tended to consume less feed and gained slower and less efficiently than pigs from sows fed starch, although the differences were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

5.
A regression approach was used to assess quantitatively the influence of lysine and ME intake during lactation on yield of milk components and to determine whether this influence was mediated through precursor metabolite concentrations in the blood. The influence of lysine and energy intake on sow weight and backfat loss also was analyzed by linear regression. Twenty-three primiparous Landrace x Yorkshire sows were fed one of nine corn-soybean meal diets to achieve a matrix of lysine (15, 30, or 45 g/d) and ME (6.5, 11.5, or 16.5 Mcal/d) intakes. Sow BW and backfat losses were found to be predominantly controlled by ME intake (P less than .02), with no response to lysine intake (P greater than .92). Lysine and ME intake explained a smaller portion of the variability in milk component yield on d 8 (R2 less than .34) than on d 22 (R2 = .64 to .78), evidence that dietary effects of milk production increased as lactation progressed. Lysine and ME intake had an interactive influence (P less than .05) on yield of all milk components except lactose, demonstrating that the amount of lysine required to maximize milk production increased as ME intake increased. Strong relationships between diet and most blood precursor metabolite concentrations (R2 = .5 to .7) were detected on d 22. No obvious relationships between precursor metabolite concentrations and milk component yield (R2 = .05 to .2) were observed. These results describe quantitatively the prominent interactive effects of lysine and ME intake on yield of milk components and demonstrate that these effects are not directly associated with changes in precursor pool concentrations.  相似文献   

6.
Yield and composition of milk and growth of nursing pigs in response to dietary treatment were estimated from 25 lactating sows during a 22-d period. Eight sows were fed 6 kg/d of a corn-soybean control diet (C sows). Nine were fed the control diet in which approximately 6.5 g X kg body weight (BW-1) X d-1 of carbohydrate was supplied by fructose corn syrup (F sows) and eight were fed the control diet containing equivalent carbohydrate supplied by powdered dextrose (D sows). Blood samples collected via jugular cannulae were analyzed for plasma concentrations of fructose, glucose and insulin. Concentrations of fructose and glucose from F sows were significantly higher throughout the study than that from D and C sows, while insulin concentration was approximately 2.5-fold lower. Milk yield from F sows on d 14 and 21 was significantly higher and pigs weaned on d 21 were heavier than those from D and C sows. Sows fed the diet containing fructose experienced significant BW loss during lactation. Coefficients of gross correlation across treatments showed milk yield and litter weight gain to be negatively associated with percentages of protein, lipids and total solids in milk, but positively associated with concentrations of lactose and gross energy. Nursing pig weight gain at weaning was more responsive to total yields of milk and milk nutrients than to composition. These data support the hypothesis that source of metabolizable energy (ME) affects milk yield, composition and efficiency at which the sow converts dietary nutrients into milk.  相似文献   

7.
Sixty-four Large White x Landrace primiparous sows were utilized to evaluate the influence of feeding 6 vs 9 Mcal ME/d during gestation on reproductive performance. The sows remained on their respective gestation diets for four parities if they successfully farrowed, rebred and conceived. Sows fed 9 Mcal ME/d gained more weight (P less than .05) through the gestation period during parities 1 and 2 and were heavier (P less than .01) on d 110 of gestation for combined parities. Lactation weight loss was greater (P less than .05) for the sows fed 9 Mcal ME/d, resulting in similar weights at weaning. Ultrasonic backfat measurements were greater (P less than .01) on d 110 of gestation for sows fed 9 Mcal ME/d during parity 1 and remained higher (P less than .01) through the fourth-parity gestation. Although sow weaning weights were similar, sows receiving 6 Mcal ME/d scanned less backfat thickness. Gestation treatment significantly affected consumption of a common lactation diet provided ad libitum. Sows fed 6 Mcal ME/d during gestation consumed an average of 22 kg more feed (P less than .01) during lactation than those sows receiving 9 Mcal ME/d. Litter performance as measured by number and weights of pigs born alive and weaned was not altered (P greater than .10) by gestation energy intake. Days to return to estrus and the number of sows remaining in the study for four parities were similar (P greater than .10) between the two treatment groups. The number of farrowings for the four parities totaled 164, with 83 and 81 farrowings for the sows fed 6 and 9 Mcal ME/d, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

8.
The impact of amino acid nutrition during lactation on body nutrient mobilization and milk nutrient output in primiparous sows was evaluated. Thirty-six sows, nursing litters of 13 pigs, were allocated daily 6 kg of a fortified corn-soybean meal diet containing a high (HP, 1.20% lysine) or low (LP, .34% lysine) protein content during a 23-d lactation. Dietary lysine concentration was achieved by altering the ratio of corn and soybean meal in the diet. The LP sows consumed less daily ME (14.2 vs 16.1 Mcal; P < .11) and daily lysine (16 vs 59 g; P < .01) than the HP sows. Daily litter weight gain was less (P < .01) for sows fed the LP vs HP diet, and the differences increased (P < . 01) as lactation progressed. The lower litter weight gain for the LP sows was reflective of the lower (P < .01) estimated milk DM, CP, and GE output of these sows. The LP sows lost more body weight (1.23 vs .21 kg/d; P < .01) during the initial 20 d of lactation. In the LP sows, 59% of the weight loss was protein, water, and ash, and 37% was fat. Weight loss in the HP sows was entirely accounted for by body fat mobilization, because these sows accrued body protein, water, and ash. Muscle myofibrillar breakdown rate was higher in LP sows than in HP sows (4.05 vs 2.80%/d; P < .01). On the basis of these data, dietary amino acid restriction during lactation increases maternal mobilization of proteinaceous tissue and reduces milk nutrient output. Maternal protein mobilization is maintained over the entire lactation even though milk output is decreased as lactation progresses.  相似文献   

9.
A total of 335 lactating sows (Landrace × Large White) were used in two experiments to determine the optimum ratio of standardized ileal digestible lysine (SID-Lys) to metabolizable energy (ME) for mixed parity sows during lactation. In Exp. 1, 185 sows (weighing an average of 256.2 ± 6.5 kg and having an average parity of 3.4 ± 0.3) were allocated to one of six experimental diets in a completely randomized block design within parity groups (1, 2, and 3+). The experimental diets were formulated to contain 3.06, 3.16, 3.20, 3.25, 3.30 or 3.40 Mcal/kg of ME and each diet was fed to the sows throughout a 28 day lactation. All diets provided a similar SID-lysine level (0.86%). As a result, the diets provided a SID-Lys:ME ratio of 2.81, 2.72, 2.69, 2.65, 2.61 or 2.53 g/Mcal ME. Sow feed intake was significantly (P < 0.01) affected by the energy content of the diet as well as by sow parity. Using regression analysis, feed intake was shown to be maximized at 3.25, 3.21, 3.21 and 3.21 Mcal/kg of ME for parity 1, 2, 3+ sows and the entire cohort of sows respectively (quadratic; P < 0.01). In addition, the result of feed intake can be expressed as 2.65, 2.69, 2.69 and 2.68 g/Mcal based on analysis of SID-Lys:ME ratio. Litter weight gain was affected by dietary treatment for parity 3+ sows and the entire cohort (P < 0.01). Based on regression analysis, litter weight gain was maximized at 3.25 and 3.24 Mcal/kg of ME for parity 3+ (quadratic; P < 0.01) and the entire cohort (quadratic; P < 0.01). Similarly, the result of litter weight gain could be expressed as 2.65 and 2.66 g/Mcal of SID- Lys:ME ratio. Therefore, 3.25 Mcal/kg of ME was selected for Exp. 2 in which 150 sows (weighing 254.6 ± 7.3 kg and having an average parity of 3.4 ± 0.4) were allocated to one of five treatments in a completely randomized block design within parity (1, 2, and 3+). The experimental diets were formulated to contain 2.1, 2.4, 2.7, 3.0 or 3.3 g/Mcal of SID-Lys:ME ratio with all diets providing 3.25 Mcal/kg of ME. The diets were fed to the sows throughout a 28 day lactation. Sow body weight loss was affected by dietary treatment (parity 3+ sows, P = 0.02; entire cohort, P < 0.01) and by sow parity (P < 0.01). Litter weight at weaning and litter weight gain were affected by dietary treatment for parity 1, 2, 3+ sows and the entire cohort (P < 0.01) as well as by sow parity (P < 0.01). Plasma urea nitrogen (P < 0.01), creatinine (P < 0.01) and non-esterifide fatty acids (P = 0.04) were decreased as the SID-Lys:ME ratio of the diet increased. Insulin-like growth factor-1 (P = 0.02), estradiol (P < 0.01) and luteinizing hormone (P = 0.02) were increased as the SID-Lys:ME ratio in diet increased. Based on a broken-line model, the estimated SID-Lys: ME ratio to maximize litter weight gain was estimated to be 3.05 g/Mcal.  相似文献   

10.
ABSTRACT: A total of 335 lactating sows (Landrace × Large White) were used in two experiments to determine the optimum ratio of standardized ileal digestible lysine (SID-Lys) to metabolizable energy (ME) for mixed parity sows during lactation. In Exp. 1, 185 sows (weighing an average of 256.2 ± 6.5 kg and having an average parity of 3.4 ± 0.3) were allocated to one of six experimental diets in a completely randomized block design within parity groups (1, 2, and 3+). The experimental diets were formulated to contain 3.06, 3.16, 3.20, 3.25, 3.30 or 3.40 Mcal/kg of ME and each diet was fed to the sows throughout a 28 day lactation. All diets provided a similar SID-lysine level (0.86%). As a result, the diets provided a SID-Lys:ME ratio of 2.81, 2.72, 2.69, 2.65, 2.61 or 2.53 g/Mcal ME. Sow feed intake was significantly (P < 0.01) affected by the energy content of the diet as well as by sow parity. Using regression analysis, feed intake was shown to be maximized at 3.25, 3.21, 3.21 and 3.21 Mcal/kg of ME for parity 1, 2, 3+ sows and the entire cohort of sows respectively (quadratic; P < 0.01). In addition, the result of feed intake can be expressed as 2.65, 2.69, 2.69 and 2.68 g/Mcal based on analysis of SID-Lys:ME ratio. Litter weight gain was affected by dietary treatment for parity 3+ sows and the entire cohort (P < 0.01). Based on regression analysis, litter weight gain was maximized at 3.25 and 3.24 Mcal/kg of ME for parity 3+ (quadratic; P < 0.01) and the entire cohort (quadratic; P < 0.01). Similarly, the result of litter weight gain could be expressed as 2.65 and 2.66 g/Mcal of SID-Lys:ME ratio. Therefore, 3.25 Mcal/kg of ME was selected for Exp. 2 in which 150 sows (weighing 254.6 ± 7.3 kg and having an average parity of 3.4 ± 0.4) were allocated to one of five treatments in a completely randomized block design within parity (1, 2, and 3+). The experimental diets were formulated to contain 2.1, 2.4, 2.7, 3.0 or 3.3 g/Mcal of SID-Lys:ME ratio with all diets providing 3.25 Mcal/kg of ME. The diets were fed to the sows throughout a 28 day lactation. Sow body weight loss was affected by dietary treatment (parity 3+ sows, P = 0.02; entire cohort, P < 0.01) and by sow parity (P < 0.01). Litter weight at weaning and litter weight gain were affected by dietary treatment for parity 1, 2, 3+ sows and the entire cohort (P < 0.01) as well as by sow parity (P < 0.01). Plasma urea nitrogen (P < 0.01), creatinine (P < 0.01) and non-esterifide fatty acids (P = 0.04) were decreased as the SID-Lys:ME ratio of the diet increased. Insulin-like growth factor-1 (P = 0.02), estradiol (P < 0.01) and luteinizing hormone (P = 0.02) were increased as the SID-Lys:ME ratio in diet increased. Based on a broken-line model, the estimated SID-Lys:ME ratio to maximize litter weight gain was estimated to be 3.05 g/Mcal.  相似文献   

11.
Twenty-two primiparous Yorkshire sows were used to determine whether a minimal threshold of body fat exists below which the return to estrus is delayed. A second objective was to examine the relationship between body fat and interval from weaning to estrus in restricted-fed sows. During lactation (28 d), sows received 7, 9, 11 or 13 Mcal of ME daily to produce a range of sow body fatness at weaning. Intake of all dietary essentials except ME was similar for all sows. Litter size was adjusted to 10 pigs for all sows by d 3 postpartum. Each day from weaning to estrus, sows received 110 kcal ME per kg metabolic body weight plus 1,359 kcal ME per sow. Body fat was estimated at weaning and at first postweaning estrus by deuterium oxide dilution. Last rib backfat depth was determined ultrasonically 24 h postpartum and at weaning. Irrespective of dietary ME intake, percentage body fat at weaning (R2 = .24; P less than .05) and first postweaning estrus (R2 = .03; P greater than .50) accounted for only a small portion of variation in interval from weaning to estrus. Likewise, loss of backfat depth during lactation was not an accurate predictor of interval from weaning to estrus (R2 = .24; P less than .05). The low coefficients of determination (less than .25) suggest that body fat is a minor controller of postweaning interval to estrus. In contrast, dietary ME intake during lactation accounted for the largest portion of the variation (R2; = .48; P less than .01) in postweaning interval to estrus. We conclude that timing of postweaning estrus in primiparous sows is not dependent on a minimal threshold of body fat. Furthermore, effects of lactational ME intake on the postweaning interval to estrus are more pronounced than the effects of body fat.  相似文献   

12.
One-hundred-three multiparous sows were randomly assigned to one of two lactation diets containing either no supplemental animal fat (C) or 10% added fat (F) during two seasons, summer (S) and winter (W), in a 2 X 2 factorial arrangement of treatments. Sows were placed on their respective dietary treatments 1 wk prior to farrowing and were fed these diets ad libitum throughout the 28-d lactation period. Weekly feed intake and total feed intake were not affected by diet or season, while weekly metabolizable energy (ME) intake tended to be higher during week 1 and 3, and was higher (P less than .04) during wk 2 for sows fed diet F. Sow weight loss from farrowing to 21 d of lactation and to weaning (28 d) were unaffected by diet or season. Average pig birth weight was .15 kg higher (P less than .01) for pigs born during S compared with those born in W. Sows receiving diet F had heavier litters at 21 d (P less than .01) and heavier average pig 21-d weights (P less than .01). This was primarily due to the 13.1% increase (P less than .04) in estimated milk yield and the higher fat concentration (P less than .001) of milk consumed by the pigs nursing sows fed diet F. Interval between weaning and rebreeding was shortened by 5.9 d (P less than .01) for sows during W than during S, and tended to be lower for sows fed diet F (7.3 d) compared with that of sows fed diet C (9.7 d).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

13.
The effects of energy and protein intakes by 32 primiparous sows during a 28-d lactation on sow and litter performance and sow body composition and bone properties were examined. Dietary treatments were energy intakes of 8 (LE) and 16 (HE) Mcal of ME/d and protein intakes of 380 (LP) and 760 (HP) g of CP/d in a 2 x 2 factorial arrangement. Sows fed diets that were inadequate in either energy or protein lost more weight than did sows fed the HE-HP diet, but backfat losses were greater when energy intake was deficient than when protein was deficient. Carcass measurements were influenced in a similar manner, with energy intake affecting (P less than .001) backfat thickness and protein intake affecting (P less than .05) longissimus muscle area. Heart, kidneys and liver of sows fed LP diets weighed less (P less than .01) and contained less water and protein (P less than .05) than those of sows fed HP. Sows fed LE had heart, liver and viscera that weighed less (P less than .05) than those of sows fed HE. There was less fat (P less than .05) in the heart, lung, liver and viscera of sows fed LE than in those of sows fed HE. Carcass components of the supraspinatus muscle and standardized sections through the longissimus muscle and right shoulder weighed less (P less than .05) from sows fed LP rather than HP, and these components contained less water and protein. Sows fed the LE diets had less fat in the loin soft tissue section, right shoulder section and supraspinatus muscle than sows fed HE. Bone composition and strength were not influenced by dietary treatment. The composition of weight lost during lactation was diet-dependent. Sows fed diets that were deficient in protein but adequate in energy lost large amounts of protein from muscles and internal organs. Energy deficiency resulted primarily in fat loss.  相似文献   

14.
Crossbred barrows (n = 336 Newsham Hybrids) initially 9.9 kg and 31+/-2 d of age were used to evaluate the effects of energy density and lysine:calorie ratio on growth performance. Pigs were allotted by initial weight in a 3 x 4 factorial arrangement of treatments in a randomized complete block design with six replicate pens per treatment. Each pen had four or five pigs with an equal number of pigs per pen within replicate. Pigs were fed increasing dietary energy densities (3.25, 3.38, and 3.51 Mcal ME/kg) and lysine:calorie ratios (3.00, 3.45, 3.90, and 4.35 g lysine/Mcal ME). Energy density was changed by levels of choice white grease (0, 3, and 6%), and lysine:calorie ratio was changed by altering the corn:soybean meal ratio. Over the 21-d trial, an energy density x lysine:calorie ratio interaction was observed for ADG (P < .05). Pigs fed diets containing 3.25 or 3.51 Mcal ME/kg had increasing ADG with increasing lysine:calorie ratio, whereas ADG of pigs fed 3.38 Mcal ME/kg was not affected by lysine:calorie ratio. Feed efficiency (gain:feed ratio) increased and ADFI decreased as lysine:calorie ratio increased (linear, P < .01) and as energy density increased (quadratic, P < .01 and .10, respectively). On d 21, two pigs per pen were scanned ultrasonically for backfat depth. An energy density x lysine:calorie ratio interaction (P < .06) was observed. Pigs fed diets containing 3.25 and 3.38 Mcal ME/kg had decreasing fat depth as lysine:calorie ratio increased; however, backfat depth was not affected by lysine:calorie ratio and was greatest for pigs fed 3.51 Mcal ME/kg. These results suggest that 10- to 25-kg pigs fed diets containing 3.38 Mcal ME/kg had maximum feed efficiency and that they required at least 4.35 g lysine/Mcal ME. However, pigs fed 3.51 Mcal ME/kg had increased fat depth regardless of calorie:lysine ratio.  相似文献   

15.
The effects of high ambient temperature and level of dietary heat increment on sow milk production and piglet performance over a 28-d lactation were determined in 59 multiparous crossbred Large White x Landrace pigs kept at a thermoneutral (20 degrees C) or in a hot (29 degrees C) constant ambient temperature. Experimental diets fed during lactation were a control diet (NP; 17.6% CP) and two low-protein diets obtained by reduction of CP level (LP; 14.2% CP) or both reduction of CP and addition of fat (LPF; 15.2% CP); the NE:ME ratio was 74.3, 75.6, and 75.8% for NP, LP, and LPF diets, respectively. All diets provided 0.82 g of digestible lysine/MJ of NE, and ratios between essential AA and lysine were above recommendations. Creep feed was provided after d 21 of lactation. Reduction of CP level did not influence (P > 0.10) milk production, milk composition, or piglet performance. Despite higher nursing frequency (39 vs 34 sucklings per day), milk production decreased (P < 0.01) from 10.43 to 7.35 kg/d when temperature increased from 20 to 29 degrees C. At d 14, DM (18.6 vs 18.1%) and energy (4.96 vs 4.75 MJ/kg) contents in milk tended (P = 0.09) to be higher in sows kept at 29 degrees C. Over the 28-d lactation, piglet BW gain and BW at weaning decreased (P < 0.01) from 272 to 203 g/d and 9.51 to 7.52 kg, respectively, when temperature increased from 20 to 29 degrees C. Daily creep feed intake over the 4th wk of lactation was higher (P < 0.01) at 29 degrees C than at 20 degrees C (388 vs 232 g/litter, respectively), which was reflected in a greater increase in BW gain between wk 1 to 3 and wk 4 at the higher temperature (147 vs 130%); BW gain between weaning and d 14 postweaning was higher (P < 0.05) for piglets originating from sows kept at 29 degrees C (280 vs 218 g/d). In connection with their lower growth rate, DM (31.2 vs 33.0%), protein (15.5 vs 16.0%), lipid (12.3 vs 13.9%), and energy (8.39 vs 9.09 kJ/g) contents in weaned, slaughtered piglets were lower (P < 0.01) at 29 than at 20 degrees C. In conclusion, modification in the CP:NE ratio in order to decrease dietary heat increment did not affect milk production and piglet performance in thermoneutral or hot climatic conditions. Our results confirm the negative effect of high ambient temperatures on milk yield and emphasize the importance of creep feed supply to improve pre- and postweaning growth of piglets in these conditions, especially when weaning occurs after 3 wk of age.  相似文献   

16.
A lactation trial involving 105 sows was conducted to determine the effect of 12% roasted or raw, ground, whole, shelled peanuts on sow weight change during lactation, feed intake, piglet and litter weight gain, milk composition, and days to return to postweaning estrus. The trial was conducted using three sow groups during two farrowing seasons, summer (July to September) and winter (December to February). Diets were based on corn plus soybean meal. Diets contained either 5% animal fat or equivalent added fat from 12% roasted or raw, ground, shelled peanuts. The replacement of animal fat by roasted or raw peanuts had no effect (P greater than .20) on sow weight change, average daily feed intake during lactation or days to estrus postweaning, or on piglet weight gain or survival. Milk composition (percentage fat and protein) was not altered (P greater than .20) by source of fat in the summer; however, in the winter, sows fed roasted peanuts had higher (P less than .05) milk fat and protein percentage at 3 d postfarrowing than other treatment groups. At d 7, sows fed 12% roasted or raw peanuts had higher (P less than .05) milk protein than sows fed 5% animal fat. Sows farrowing in the summer had greater (P less than .01) weight loss and consumed less (P less than .05) feed during lactation than sows farrowing in the winter. Sows farrowed in the summer had larger (P less than .05) litters at birth and 14 d postfarrowing and greater (P less than .10) piglet and litter weight gain postfarrowing than those farrowed in the winter.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

17.
In a field trial conducted on a commercial swine farm, lean-genotype sows (n = 485) were fed diets containing 0 or 10% supplemental fat as either medium-chain triglyceride or choice white grease from d 90 of gestation until weaning (15.5 d). Effects on standard sow and litter production traits were examined together with assessment of sow body condition using live ultrasound. Daily feed intake during lactation was 10% higher in sows consuming diets without added fat (7.2 vs 6.5 kg; P < 0.01); however, lactation ME (23.9 Mcal/d) and digestible lysine (54 g/d) intakes were unaffected (P > 0.10). Sows supplemented with fat were 4 kg heavier on d 109 of gestation (220 vs 224 kg; P < or = 0.01), 1 d after farrowing (210 vs 214 kg; P < or = 0.01), and at weaning (210 vs 214 kg; P < or = 0.01). Expressed as overall gain, this amounted to a 23% increase (0.66 vs 0.86 kg/d; P < or = 0.01) and was accompanied by a 49% increase in backfat (0.82 vs 1.68 mm; P < or = 0.03) from d 90 to farrowing. Changes in sow weight (-0.01 kg/d) and backfat (+4.2 mm) over lactation were minimal and were not affected by fat supplementation (P > or = 0.10). Longissimus muscle area at weaning was slightly greater (44.96 vs 46.2 cm2) in sows consuming fat than in control sows (P < or = 0.05), but changes in longissimus muscle area were not significant from d 90 to weaning (P > or = 0.10). Gestation length, pigs born alive, average birth weight, survival (d 3 to weaning), and days to estrus were not affected by diet (P > 0.10). However, supplemental fat increased pig ADG (192 vs 203 g/d; P < 0.01) and average pig weaning weight (4.3 vs 4.5 kg) at 15.5 d (P < or = 0.02). No differences between the two fat sources were detected. This large-scale study demonstrated that supplemental fat during gestation and lactation effectively improved sow condition and improved suckling pig performance without affecting energy intake during lactation, implying improved efficiency of sow energy utilization.  相似文献   

18.
In Exp. 1 two groups of 18 sows were used to evaluate the effects of supplemental dietary fat on sow and litter performance and milk production and composition. Sows were provided ad libitum access to either a corn-soybean meal (control) diet or a similar diet containing 10% tallow. Feed intake, ME intake, and milk yield did not differ (P > .10) between treatments. The percentage of solids in milk was greater (P < .05) for sows fed the tallow diet, due to an increase (P < .05) in the fat and ash content. Compared with percentages of fatty acids in milk of sows fed the control diet, the percentages of C10:0, C14:0, C16:0, C16:1, and C18:3 fatty acids were lower (P < .05) and the percentages of C18:0 and C18:1 fatty acids were higher in milk of sows fed tallow diets (P < .05). In Exp. 2, 30 sows were fed diets similar to those fed in Exp. 1, and the effects of a tallow diet on pig carcass composition at weaning were determined. Litter size was standardized to 10 pigs. There were no differences (P > .10) in ADFI of sows. Daily ME intake was greater for sows fed tallow than for control sows during wk 2 (P < .05), wk 3 (P < .10), and the entire lactation (P < .05) period. Litter weaning weight was greater (P < .05) for pigs from sows fed tallow diets than for pigs from control sows. Pigs from tallow-fed sows had greater carcass fat weight and fat percentages (P < .05) and lower water and protein percentages (P < .05). These data indicate that the increased fat content of milk from sows fed tallow diets resulted in an increased weight gain for litters nursing these sows. The composition of the increased weight gain is almost exclusively fat.  相似文献   

19.
Two hundred sixteen crossbred barrows and gilts (84.3 kg BW) were used to test the effects of dietary energy density and lysine:energy ratio (Lys:ME) on the performance, carcass characteristics, and pork quality of finishing pigs fed 10 ppm ractopamine. Pigs were blocked by BW and gender, allotted to 36 pens (six pigs per pen), and pens were assigned randomly within blocks to dietary treatments (as-fed basis) arranged in a 2 x 3 factorial design, with two levels of energy (3.30 or 3.48 Mcal/kg) and three Lys:ME (1.7, 2.4, or 3.1 g lysine/Mcal) levels. Pigs were fed experimental diets for 28 d, and weights and feed disappearance were recorded weekly to calculate ADG, ADFI, and G:F. Upon completion of the feeding trial, pigs were slaughtered and carcass data were collected before fabrication. During carcass fabrication, hams were analyzed for lean composition using a ham electrical conductivity (TOBEC) unit, and loins were collected, vacuum-packaged, and boxed for pork quality data collection. Energy density had no (P > 0.22) effect on ADG or ADFI across the entire 28-d feeding trial; however, pigs fed 3.48 Mcal of ME were more (P < 0.02) efficient than pigs fed 3.30 Mcal of ME. In addition, ADG and G:F increased linearly (P < 0.01) as Lys:ME increased from 1.7 to 3.1 g/Mcal. Carcasses of pigs fed 3.48 Mcal of ME were fatter at the last lumbar vertebrae (P < 0.08) and 10th rib (P < 0.04), resulting in a lower (P < 0.03) predicted fat-free lean yield (FFLY). Conversely, 10th-rib fat thickness decreased linearly (P = 0.02), and LM depth (P < 0.01) and area (P < 0.01) increased linearly, with increasing Lys:ME. Moreover, FFLY (P < 0.01) and actual ham lean yield (P < 0.01) increased as Lys:ME increased in the diet. Dietary energy density had no (P > 0.19) effect on pork quality, and Lys:ME did not (P > 0.20) affect muscle pH, drip loss, color, and firmness scores. Marbling scores, as well as LM lipid content, decreased linearly (P < 0.01) as Lys:ME increased from 1.7 to 3.1 g/Mcal. There was a linear (P < 0.01) increase in shear force of cooked LM chops as Lys:ME increased in the finishing diet. Results indicate that 3.30 Mcal of ME/kg (as-fed basis) is sufficient for optimal performance and carcass leanness in pigs fed ractopamine. The Lys:ME for optimal performance and carcass composition seems higher than that currently used in the swine industry; however, feeding very high Lys:ME (> 3.0 g/Mcal, as-fed basis) to ractopamine-fed pigs may result in decreased marbling and cooked pork tenderness.  相似文献   

20.
The effects of dietary fat or fructose supplementation during late gestation and lactation on sow milk production and composition and on progeny were examined. On d 88 of gestation, 24 sows were allotted by parity to three dietary treatments (eight sows/treatment). Treatments were 1) a 12.5% crude protein, corn-soybean meal control, 2) the control + 10% added fat or 3) the control + 23% high fructose corn syrup. All treatments were fed to supply 1.82 kg/d of the control diet from d 89 of gestation to parturition with sows in treatments 2 or 3 receiving .18 kg of additional fat or .53 kg of additional high fructose corn syrup, respectively. Feed was gradually increased from d 1 to 7 of lactation to 4.54 kg/d of the control diet (plus .45 kg of added fat and 1.33 kg of added fructose for treatments 2 and 3) and remained at these levels for the remainder of the 21 d lactation period. All treatments were iso-nitrogenous; treatments 2 and 3 were iso-caloric. Litter birth weights, number of pigs born alive, weaning weights and piglet survival rate were not affected by sow treatment. Stillbirths were less (P less than .05) for sows fed fat. Lipid content of milk 24 h post-farrowing was greater (P less than .05) from sows fed fat compared with sows fed fructose. Milk production estimates indicated that multiparous sows fed fat produced more (P less .05) milk than sows fed the control diet. On d 112 of gestation and d 15 of lactation, serial blood samples were drawn to monitor sow response to a glucose challenge (1 g/kg body weight).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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